[cheese] cheese-window: Add camera toggle button

[David King <davidk src gnome org>]

commit b1dccccafedd4025650a32aa8d915dc3415d5121
Author: Jan-Michael Brummer <jan brummer tabos org>
Date:   Tue May 1 22:48:43 2018 +0200

    cheese-window: Add camera toggle button
    
    Fixes: https://bugzilla.gnome.org/show_bug.cgi?id=750285

 data/cheese-main-window.ui |   19 ++++++++-
 src/cheese-window.vala     |   93 +++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 109 insertions(+), 3 deletions(-)
---
diff --git a/data/cheese-main-window.ui b/data/cheese-main-window.ui
index c0ff90f..bdaf5a1 100644
--- a/data/cheese-main-window.ui
+++ b/data/cheese-main-window.ui
@@ -35,12 +35,12 @@
                   <object class="GtkGrid" id="buttons_area">
                     <property name="border-width">6</property>
                     <property name="orientation">horizontal</property>
+                    <property name="column-spacing">6</property>
                     <property name="visible">True</property>
                     <child>
                       <object class="GtkBox" id="mode_toggle_buttons">
                         <property name="orientation">horizontal</property>
                         <property name="halign">start</property>
-                        <property name="hexpand">True</property>
                         <property name="visible">True</property>
                         <style>
                           <class name="linked"/>
@@ -87,11 +87,27 @@
                       </packing>
                     </child>
                     <child>
+                      <object class="GtkButton" id="switch_camera_button">
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="receives_default">True</property>
+                        <property name="halign">start</property>
+                        <child>
+                          <object class="GtkImage">
+                            <property name="visible">True</property>
+                            <property name="can_focus">False</property>
+                            <property name="icon_name">camera-switch-symbolic</property>
+                          </object>
+                        </child>
+                      </object>
+                    </child>
+                    <child>
                       <object class="GtkButton" id="take_action_button">
                         <property name="action-name">app.shoot</property>
                         <property name="tooltip_text" translatable="yes">Take a photo using a 
webcam</property>
                         <property name="halign">center</property>
                         <property name="visible">True</property>
+                        <property name="hexpand">True</property>
                         <style>
                           <class name="image-button"/>
                         </style>
@@ -107,7 +123,6 @@
                       <object class="GtkBox" id="effects_actions_pack">
                         <property name="orientation">horizontal</property>
                         <property name="halign">end</property>
-                        <property name="hexpand">True</property>
                         <property name="visible">True</property>
                         <style>
                           <class name="linked"/>
diff --git a/src/cheese-window.vala b/src/cheese-window.vala
index 50e024b..09879fc 100644
--- a/src/cheese-window.vala
+++ b/src/cheese-window.vala
@@ -73,6 +73,8 @@ public class Cheese.MainWindow : Gtk.ApplicationWindow
     private Gtk.ToggleButton effects_toggle_button;
     [GtkChild]
     private Gtk.Widget buttons_area;
+    [GtkChild]
+    private Gtk.Button switch_camera_button;
     private Gtk.Menu thumbnail_popup;
 
     private Clutter.Stage viewport;
@@ -1213,6 +1215,92 @@ public class Cheese.MainWindow : Gtk.ApplicationWindow
     }
 
   /**
+   * Select next camera in list and activate it.
+   */
+  public void on_switch_camera_clicked ()
+  {
+      Cheese.CameraDevice selected;
+      Cheese.CameraDevice next = null;
+      GLib.PtrArray cameras;
+      uint i;
+
+      if (camera == null)
+      {
+          return;
+      }
+
+      selected = camera.get_selected_device ();
+
+      if (selected == null)
+      {
+          return;
+      }
+
+      cameras = camera.get_camera_devices ();
+
+      for (i = 0; i < cameras.len; i++)
+      {
+          next = (Cheese.CameraDevice )cameras.index (i);
+
+          if (next == selected)
+          {
+              break;
+          }
+      }
+
+      if (i + 1 < cameras.len)
+      {
+          next = (Cheese.CameraDevice )cameras.index (i + 1);
+      }
+      else
+      {
+          next = (Cheese.CameraDevice )cameras.index (0);
+      }
+
+      if (next == selected)
+      {
+          /* Next is the same device.... */
+          return;
+      }
+
+      camera.set_device (next);
+      camera.switch_camera_device ();
+  }
+
+  /**
+   * Set switch camera buttons visible state.
+   */
+  public void set_switch_camera_button_state ()
+  {
+      Cheese.CameraDevice selected;
+      GLib.PtrArray cameras;
+
+      if (camera == null)
+      {
+          switch_camera_button.set_visible (false);
+          return;
+      }
+
+      selected = camera.get_selected_device ();
+
+      if (selected == null)
+      {
+          switch_camera_button.set_visible (false);
+          return;
+      }
+
+      cameras = camera.get_camera_devices ();
+
+      if (cameras.len > 1)
+      {
+         switch_camera_button.set_visible (true);
+         return;
+      }
+
+      switch_camera_button.set_visible (false);
+  }
+
+  /**
    * Load the UI from the GtkBuilder description.
    */
   public void setup_ui ()
@@ -1277,6 +1365,8 @@ public class Cheese.MainWindow : Gtk.ApplicationWindow
 
     thumb_view.button_press_event.connect (on_thumbnail_button_press_event);
 
+    switch_camera_button.clicked.connect (on_switch_camera_clicked);
+
     /* needed for the sizing tricks in set_wide_mode (allocation is 0
      * if the widget is not realized */
     viewport_widget.realize ();
@@ -1368,5 +1458,6 @@ public class Cheese.MainWindow : Gtk.ApplicationWindow
     public void set_camera (Camera camera)
     {
         this.camera = camera;
-    }
+        set_switch_camera_button_state ();
+     }
 }